Which of the following is an example of homogeneous equilibrium ?

Options

A. `2SO_(2(g))+O_(2(g))hArr2SO_(3(g))`
B. `C_((s))+H_(2)O_((g))hArrCO_((g))+H_(2(g))`
C. `CaCO_(3(s))hArrCaO_((s))+CO_(2(g))`
D. `NH_(4)NS_((s))hArrNH_(3(g))+H_(2)S_((g))`

Answer

To determine which of the given options is an example of homogeneous equilibrium, we need to understand what homogeneous equilibrium is. Homogeneous equilibrium occurs when all the reactants and products in a chemical reaction are in the same physical state (i.e., all gases, all liquids, or all solids).

### Step-by-Step Solution:

1. **Understand Homogeneous Equilibrium**:
- Homogeneous equilibrium involves reactants and products that are all in the same phase (state).

2. **Analyze the Options**:
- **Option 1**: \(2SO_2(g) + O_2(g) \rightarrow 2SO_3(g)\)
- All species (reactants and products) are gases. This is homogeneous equilibrium.
- **Option 2**: \(C(s) + S_2O(g) \rightarrow \)
- Here, we have solid carbon and gaseous sulfur dioxide. Since they are in different states, this is heterogeneous equilibrium.
- **Option 3**: \(CaCO_3(s) \rightarrow CaO(s) + CO_2(g)\)
- The reactant is solid and one of the products is gas. This is also heterogeneous equilibrium.
- **Option 4**: \(C(s) + O_2(g) \rightarrow CO_2(g)\)
- Again, we have solid carbon and gaseous oxygen, which means this is heterogeneous equilibrium.

3. **Identify the Correct Option**:
- From the analysis, only **Option 1** \(2SO_2(g) + O_2(g) \rightarrow 2SO_3(g)\) is an example of homogeneous equilibrium.

### Conclusion:
The correct answer is **Option 1**: \(2SO_2(g) + O_2(g) \rightarrow 2SO_3(g)\).

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